Saying goodbye to the crunch

Photograph by: Vincenzo D'Alto
, The Gazette

MONTREAL — Despite the suggestion by several fitness experts that the crunch should be permanently retired, there are still plenty of fitness fanatics hammering out hundreds of reps a week.

Whether their devotion is based on the belief that there’s no better way to get a set of washboard abs, or they just can’t imagine a workout that doesn’t include a couple dozen crunches, it’s time to realize that this iconic exercise doesn’t offer a lot of bang for the buck.

Sure, the crunch used to be a fitness mainstay back in the day when ab workouts were all the rage. But those days are gone. Nowadays we do more than just train our abs, we train our whole core.

Defined as the area between our shoulders and hips, the core includes all the muscles located along the front, back and sides of our torso including those deep within the core structure itself. And, unlike the ab training of old, which focused primarily on the rectus abdominis, the long length of muscle that runs from the sternum to the pubic bone, today’s core workouts train all the muscles in unison, mimicking the synergistic way the core functions in daily life.

Interestingly, that singular focus on a specific muscle, which is what made crunches the alpha dog of all ab exercises, is the primary reason why the crunch has fallen out of favour.

But that’s not the only basis for its fall. Several exercise physiologists, in particular biomechanics expert Stuart McGill from the University of Waterloo, claim that too many crunches can lead to overuse injuries of the spine.

The trouble with changing our focus from the abs to the core means that we need more than just one exercise to target all those muscles, which translates into spending more time getting our midsection into shape. Or does it?

A research team from the Department of Kinesiology at Pennsylvania State University measured the amount of activity in six muscles during a series of core exercises including the crunch and a few others designed to target one or more muscles of the core.

The subjects were 20 college-age students, 10 men and 10 women, all of whom performed the exercises with small electrodes adhered to their body. The readings from those electrodes determined not only which muscles fired, but also just how hard each muscle worked during the execution of the individual exercises.

Not surprising for fitness experts who have been singing this tune for a few years now, the crunch didn’t fare so well in terms of the amount of muscle activity it generated compared to other exercises in the study. What was surprising however, is that even when focusing on just the rectus abdominis, the muscle the crunch was thought to isolate so effectively, there were several other exercises that worked it harder.

For example, the plank with lateral arm reach elicited 27 per cent more activity in the rectus abdominis than the crunch. The muscles in the shoulder and the lower back also worked harder during the plank, generating twice as much muscle activity than they did during the crunch.

Eliciting the greatest amount of muscle activity out of the seven exercises tested was the mountain climber plank. The exercise, which moves a traditional plank from the forearms to the hands and adds the dynamic of bringing the bent knee to the opposite elbow, demanded seven per cent greater activation of the rectus abdominis and the shoulder than did the plank with lateral arm reach. It also demanded 11 per cent more activity in the muscles that run along the sides of the torso and 70 per cent more activity in the gluteus maximus (the buttocks) than did the plank.

One of the main reasons the crunch fared so poorly is that the other exercises, like both planks, required more balance and stability, not to mention that they also required the exerciser to support their own body weight. The more balance required, the more muscles required. And the more body weight we need to support, the more demand we place on those muscles.

For those into their middle years and beyond, the addition of balance requirements to an exercise increases its functional benefits.

Balance deteriorates as we age, so any exercise that improves our ability to balance is worthwhile. Too bad crunches don’t fit into that category.

So for anyone out there who still thinks their workout isn’t complete without doing a few crunches, it’s time to reconsider your game plan.

Replacing the crunch with the plank with lateral arm reach or the mountain climber plank will benefit you in more ways than just saving your spine from too many forward bends. Choosing an exercise that targets more than just your abs is a more efficient and effective way to train your core.

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